1. Field of the Invention
The present invention relates to an electronic device provided with a metal fluoride film.
2. Description of Related Art
The conventional technology will be explained using the example of a semiconductor device as the electronic device.
Conventionally, among semiconductor devices, devices are known which utilize a silicon oxide film formed by the CVD method as an insulating film. In the case in which the insulating film is for the purpose of insulating and separating between electrodes, this insulating film is formed by the accumulation on a substrate of a silicon oxide layer, by means of bringing gas-containing silicon atoms and gas-containing oxygen molecules into contact with the surface of the silicon, metal, metal silicide, or silicon oxide film on a silicon substrate at high temperatures (for example, at temperatures of more than 400.degree. C.).
However, this insulating film has problems in that the temperature at which formation occurs must be high, and a low-temperature process has not been realized.
Hereinbelow, the need for a low temperature process will be explained, taking as an example the formation of a MOSLSI insulating film.
The pace of development in the field of LSI technology has been extremely high, and DRAMs of more than 1 Mbit have already been realized. In the production of such high performance electronic devices, that is to say, devices which are very fine and have a very high degree of integration, it is clear that a high performance production process which has few undesirable effects on indeterminate elements and is more subject to control is necessary. Low temperature processes have been suggested for use as this high performance process.
For example, a lowering of the process temperature is effective in reducing warping of the silicon substrate, deformation in the material of the silicon device construction, and defect density.
Furthermore, if the formation temperature of the insulating film is lower than approximately 400.degree. C., it becomes possible to form the insulating film after the formation of a metal or alloy having a low melting point (for example, an aluminum alloy), so that semiconductor devices having various functions can be realized. In particular, if the temperature is below 400.degree. C., for example, in the case of a thin aluminum film, as a hillock is not formed, this is particularly effective. As stated above, a lowering of the temperature at which the insulating film is formed is necessary for the realization of ultra LSI.
However, in the prior art, as only high temperature processes existed, ultra LSI and high performance semiconductor devices could not be realized.
Furthermore, in the prior art, for example, in the case in which an interlayer insulating film (a silicon oxide film) was formed in an MOS, a silicon oxide film was formed over the entire surface by means of the CVD method. However, in the case of this insulating film, at the time of the formation of contact holes, the use of masking to form contact holes at specified positions could not be avoided, and accordingly, processing by means of so-called "self-alignment" could not be attained, and only devices having poor processing accuracy could be realized.
It is an object of the present invention to provide an electronic device provided with metal fluoride film which can be produced by means of a low temperature process and which furthermore has a high processing accuracy.